The invention relates to a method and a system for measuring the quality of a multistep washing process using a plurality of chemicals and to measuring equipment for said system. In connection with this invention, the chemicals also include rinsing agents, such as water.
PCT publication WO 2006/073885 discloses a fluid treatment system for use with a multistep washing appliance. A controller controls solenoids, through which chemicals are dispensed into a washer. Publication WO 2006/073885 does not describe, however, on which basis the controller decides that one step is over and the next one starts.
A technique for proceeding from one step to another in a multistep washing process is to program in a controller an empirical duration for each washing step, after which a transition to a next step takes place. This operating principle applies, for instance, to household washing machines and dishwashers. In some cases a pre-programmed time may start when a condition for a washing step is fulfilled, for instance, the wash water is heated to a sufficiently high temperature.
A problem with this technique is how to rate optimally the durations of different steps in the multistep washing process. If the durations are too short, the wash result is poor, whereas excessively long wash times consume time and energy unnecessarily.